US 12,315,919 B2
Cathode active material for lithium secondary battery and lithium secondary battery including the same
Ji Yae Do, Daejeon (KR); Min Suk Kang, Daejeon (KR); Min Cheol Beak, Daejeon (KR); Kwang Ho Lee, Daejeon (KR); and Jae Young Choi, Daejeon (KR)
Assigned to SK INNOVATION CO., LTD., Seoul (KR); and SK ON CO., LTD., Seoul (KR)
Filed by SK INNOVATION CO., LTD., Seoul (KR); and SK ON CO., LTD., Seoul (KR)
Filed on Jun. 29, 2023, as Appl. No. 18/343,747.
Claims priority of application No. 10-2022-0167877 (KR), filed on Dec. 5, 2022.
Prior Publication US 2024/0186489 A1, Jun. 6, 2024
Int. Cl. H01M 4/36 (2006.01); H01M 4/58 (2010.01); H01M 4/62 (2006.01); H01M 4/02 (2006.01); H01M 4/04 (2006.01)
CPC H01M 4/366 (2013.01) [H01M 4/5825 (2013.01); H01M 4/625 (2013.01); C01P 2002/52 (2013.01); C01P 2002/85 (2013.01); C01P 2004/86 (2013.01); C01P 2006/40 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01); H01M 4/0471 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A cathode active material for a lithium secondary battery comprising a plurality of a composite particle, each of which comprises:
a lithium metal phosphate particle having an olivine structure and is represented by Chemical Formula 1:
LiaMxPyO4+z  [Chemical Formula 1]
wherein, in Chemical Formula 1, 0.9≤a≤1.2, 0.99≤x≤1.01, 0.9≤y≤1.2, −0.1≤z≤0.1, and M is a metal including at least one selected from the group consisting of Fe, Co, Ni and Mn; and
a carbon coating formed on at least a portion of a surface of the lithium metal phosphate particle;
wherein a standard deviation of thickness values of the carbon coating measured by an X-ray photoelectron spectroscopy (XPS) for five different composite particles of the plurality of the composite particle is 15 nm or less,
an average of the thickness values of the carbon coating is in a range from 5 nm to 15 nm,
a content of the carbon coating is in a range from 0.8 wt % to 1.4 wt % based on a total weight of the composite particle,
the cathode active material is made from a mixture of a lithium source, a metal phosphate, a carbon source comprising glucose, and a dispersing agent selected from group consisting of sodium hexametaphosphate, sodium tripolyphosphate, pyrophosphate, and combinations thereof, and
the glucose is in an amount of 3.5 to 17% based on the total weight of the lithium source, the metal phosphate, the glucose, and the dispersing agent, and
the dispersant agent is in an amount of 0.05 to 0.2% based on the total weight of the lithium source, the metal phosphate, the glucose, and the dispersing agent.